Leather and process for the manufacture thereof



Patented Dec. 28 1937 UNITED STATES PATENT OFFICE LEATHER AND PROCESS FOR THE MANU- FACTURE THEREOF Hugo Bohm, Munich, Germany No Drawing. Application January 23, 1937, Se-

rial No. 121,981. In Germany December 5,

5 Claims.

This invention relates to leather and a process for the manufacture thereof.

Attempts to use animal membranes, other than animal skin, for the production of leather, have, up to the present not led to a satisfactory result. It is well known to tan intestines, and the stomach or the paunch of ruminants have been treated for the production of leather.

In connection with the latter some of the stomachs have been suitable for the production of ornamental leather, whilst on the other hand leather obtained from the major portion of the stomach, mainly the rumen, have exhibited the property that they have uneven portions, so called tufts, so that they cannot beused to any large extent in this condition for commercial purposes.

The present invention shows that it has become possible to obtain a marketable leather from the stomach, this result being obtained in that the stomach is first tanned, thereupon immediately dried, that is to say not de-greased, and then the unevennesses, located on the layer of horn matter, ground off, whereupon the material which is now smooth is again softened in hot water and then de-greased. It is also possible to dry and grind the stomach before tanning after the outer muscles and mucous membranes have been removed. This is desirable in the case of chrome and grease tanning.

The leather thus obtained can be dyed, lacquered and pressed in the usual manner. For removing the tufts there are preferably used rotary brushes and emery wheels. For the purpose of drying, the tanned stomach is stretched in the wet condition, preferably in a frame.

One method of carrying the process will now be described.

The stomach is thoroughly washed and is then treated with slack lime in the usual manner. This renders possible an easy removal of the outer into effect muscles and mucous membranes with which the actual skin fibre layer of the stomach is provided. The removal of the above mentioned outer muscle and mucous membranes is effected by scraping from the stomach, for which purpose considerable care is necessary as the skin fibre layer of the leather must remain as undamaged as possible.

The tanned leather then without degreasing is stretched in the wet condition in a frame and dried. The tufts located on the grain layer or. layer of horn matter become quite brittle and can be removed easily, for which purpose some care must be taken so that the layer of horn matter is not damaged. After this operation the material thus produced, which now exhibits a completely smooth surface, is again softened in hot water then degreased and dried. 10

When chrome leather salts or fats are used for the tanning, the stomachs after being treated with slack lime must be thoroughly washed, stretched in a frame and dried. The grinding off of the uneven portions (tufts) is then effected in the frame. The dry, bare skin is then again softened in hot water and then tanned in the usual manner with chrome salts or fats. For grinding off the uneven portions (tufts) there are preferably used rotary brushes and emery wheels which for ex- 20 ample are driven in the usual manner, for example by means of an electric motor with a flexible shaft. V

The leather obtained in this manner can be dyed in the usual manner, pressed with different types of grain or also lacquered. By reason of its particular strength the leather is not only suitable for port-folios, belts and lining leather, but also as furniture and shoe leather.

I claim:

1. In a process of producing smooth surface leather from stomachs or paunches of ruminants which includes tanning the leather,'the operation of removing tufts and irregularities which comprises treating with slaked lime, stretching and drying the material Without degreasing, and abrading to remove tufts and irregularities.

2. The smooth surface ruminant or stomach leather produced according to claim 1. i v 40 3. The process of claim 1 in which the abrasion is carried out by brushes and emery wheels.

4. The process of claim 1 in which the tanning is done with vegetable tanning agents and is per- The bare skin thus obtained is then thoroughly washed. The skin is then tanned with vegetable or synthetic tanning agents.

formed before stretching and drying. 5 5. The process of claim 1 in which the tanning is done with chrome salts and fats and is performed after abrading.

HUGO B'O'HM. 

